title: Three specific antigens to isolate endothelial progenitor cells from human liposuction material.
abstract: OBJECTIVE
  Human endothelial progenitor cells (EPC) play an important role in regenerative medicine and contribute to neovascularization on vessel injury. They are usually enriched from peripheral blood, cord blood and bone marrow. In human fat tissue, EPC are rare and their isolation remains a challenge.
  
  
  METHODS
  Fat tissue was prepared by collagenase digestion, and the expression of specific marker proteins was evaluated by flow cytometry in the stromal vascular fraction (SVF). For enrichment, magnetic cell sorting was performed with the use of CD133 microbeads and EPC were cultured until colonies appeared. A second purification was performed with CD34; additional isolation steps were performed with the use of a combination of CD34 and CD31 microbeads. Enriched cells were investigated by flow cytometry for the expression of endothelial specific markers, by Matrigel assay and by the uptake of acetylated low-density lipoprotein.
  
  
  RESULTS
  The expression pattern confirmed the heterogeneous nature of the SVF, with rare numbers of CD133+ detectable. EPC gained from the SVF by magnetic enrichment showed cobblestone morphology of outgrowth endothelial cells and expressed the specific markers CD31, CD144, vascular endothelial growth factor (VEGF)R2, CD146, CD73 and CD105. Functional integrity was confirmed by uptake of acetylated low-density lipoprotein and the formation of tube-like structures on Matrigel.
  
  
  CONCLUSIONS
  Rare EPC can be enriched from human fat tissue by magnetic cell sorting with the use of a combination of microbeads directed against CD133, an early EPC marker, CD34, a stem cell marker, and CD31, a typical marker for endothelial cells. In culture, they differentiate into EC and hence could have the potential to contribute to neovascularization in regenerative medicine.
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Austrian Cluster for Tissue Regeneration, Vienna, Austria; Red Cross Blood Transfusion Service of Upper Austria, Linz, Austria.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Hager
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Holnthoner
authors.forename: Susanne
authors.initials: S
authors.lastname: Wolbank
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Husa
authors.forename: Kathrin
authors.initials: K
authors.lastname: Godthardt
authors.forename: Heinz
authors.initials: H
authors.lastname: Redl
authors.forename: Christian
authors.initials: C
authors.lastname: Gabriel
mesh_terms: D015720:5'-Nucleotidase / Q000096:biosynthesis; D000071916:AC133 Antigen; D000273:Adipose Tissue / Q000166:cytology; D015703:Antigens, CD / Q000096:biosynthesis / Q000276:immunology*; D018952:Antigens, CD34 / Q000276:immunology*; D051929:CD146 Antigen / Q000096:biosynthesis; D015820:Cadherins / Q000096:biosynthesis; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D000071063:Endoglin; D042783:Endothelial Cells / Q000166:cytology* / Q000276:immunology; D058851:GPI-Linked Proteins / Q000096:biosynthesis; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D015187:Lipectomy; D008863:Microspheres; D018919:Neovascularization, Physiologic / Q000502:physiology; D010455:Peptides / Q000276:immunology*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis* / Q000276:immunology; D011956:Receptors, Cell Surface / Q000096:biosynthesis; D013234:Stem Cells / Q000166:cytology* / Q000276:immunology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000096:biosynthesis; D000099152:Cadherin 5
chemical_list: D015720:5'-Nucleotidase; D000071916:AC133 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; D051929:CD146 Antigen; D015820:Cadherins; D000071063:Endoglin; D058851:GPI-Linked Proteins; D006023:Glycoproteins; D010455:Peptides; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011956:Receptors, Cell Surface; D040301:Vascular Endothelial Growth Factor Receptor-2; D000099152:Cadherin 5; C064206:ENG protein, human; C497902:MCAM protein, human; C000606023:PROM1 protein, human; C548241:NT5E protein, human
keywords: endothelial progenitor cells; liposuction; magnetic cell sorting; vascularization